Can't OTA do that?
Object testing arena is for... testing objects. Not for making giant dungeons and improbable megaprojects.
He means something you can just build on for adventurers or something...
That's sort of what I was thinking: a (possibly third-party) program or game mode that would allow you to specifically tailor a map the way you want it. And not necessarily editing an existing map - I mean starting a completely blank map that you could add things to, that would be independent of normal game worlds. I can understand it would be a bit strange to add a dungeon out of nowhere to an already-existing map.
Well, the problem with that is.. you can't exactly run it in adventure mode if it's not in the game world.
Giant dungeons are a good idea, it just doesn't make sense for them to spontaneously appear, or have unnamed servants build them.
I feel like it would be more along the lines of a fortress megaproject that you'd build without constraints. (Even though, in my opinion. The constraints make it !!FUN!!)
If built, it should exist in a sort from a game world.. But there needs to be sense made of it. I'm sure at least one of you has played WoW and found the dungeon monsters to have some sense to them. Like the dwarfs of the fort itself. or invaders that took it over, or a wildlife invasion.. Perhaps it was "brought forth from the underworld" and "populated with the local bears" or something like that.
But that's really only if it's not a third-party plugin. A third party plugin would just make you omnipotent, and allow you to place walls of whatever materials you please in your fort and populate it with monsters. In which you'd need to make it make sense yourself...
and come to think of it, the mazes of menace make little to no sense anyway...